1. Field of the Invention
The present invention relates to a DCT (Dual Clutch Transmission) control method of a vehicle, and more particularly, to a technology of shifting when an input shaft speed sensor of a DCT breaks down.
2. Description of Related Art
Some of DCTs mounted on vehicles calculate the output speed of a transmission by performing inverse calculation of the vehicle speed obtained by a wheel speed sensor without using an output shaft speed sensor.
Accordingly, when the input shaft speed sensor of the DCTs brakes, the slip amount is not determined in the synchronizing process for engaging a shift gear and gear shift control cannot be smoothly performed, so limp-home control of single clutch shift control (odd-to-odd/even-to-even) is performed without controlling the shaft for the broken input shaft speed sensor.
In this driving, the driving performance is remarkably decreased in comparison to a double clutch shift control, and particularly, in odd-to-odd driving, backward motion is impossible.
For reference, the ‘engaging a shift gear’ means a configuration in which, in an synchronized-engagement type shifting mechanism, the shift gears substantially forming the gear ratio are always engaged and make a pair of each shift range, when the sleeve of the synchronizing device is engaged with one shift gear of any one pair of shift gears in the pairs of shift gears engaged in advance, shifting is performed by the corresponding pair of shift gears and power is transmitted, in detail, it means that the sleeve of the synchronizing device is engaged with one shift gear for a desired shift range.
Accordingly, ‘disengagement of a shift gear’ described below means that the sleeve of the synchronizing device is substantially disengaged from a shift gear into a neutral state.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.